PROSACRadialDistortionRobustEstimator.java

/*
 * Copyright (C) 2015 Alberto Irurueta Carro (alberto@irurueta.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.irurueta.ar.calibration.estimators;

import com.irurueta.ar.calibration.RadialDistortion;
import com.irurueta.geometry.CoordinatesType;
import com.irurueta.geometry.Point2D;
import com.irurueta.geometry.estimators.LockedException;
import com.irurueta.geometry.estimators.NotReadyException;
import com.irurueta.numerical.robust.PROSACRobustEstimator;
import com.irurueta.numerical.robust.PROSACRobustEstimatorListener;
import com.irurueta.numerical.robust.RobustEstimator;
import com.irurueta.numerical.robust.RobustEstimatorException;
import com.irurueta.numerical.robust.RobustEstimatorMethod;

import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Finds the best radial distortion for provided collections of 2D points using
 * PROSAC algorithm.
 */
public class PROSACRadialDistortionRobustEstimator extends RadialDistortionRobustEstimator {

    /**
     * Constant defining default threshold to determine whether points are
     * inliers or not.
     * By default, 1.0 is considered a good value for cases where measures are
     * done on pixels, since typically the minimum resolution is 1 pixel.
     */
    public static final double DEFAULT_THRESHOLD = 1.0;

    /**
     * Minimum value that can be set as threshold.
     * Threshold must be strictly greater than 0.0.
     */
    public static final double MIN_THRESHOLD = 0.0;

    /**
     * Threshold to determine whether points are inliers or not when testing
     * possible estimation solutions.
     * The threshold refers to the amount of error (i.e. distance) a possible
     * solution has on a matched pair of points.
     */
    private double threshold;

    /**
     * Quality scores corresponding to each provided point.
     * The larger the score value the better the quality of the sample.
     */
    private double[] qualityScores;

    /**
     * Constructor.
     */
    public PROSACRadialDistortionRobustEstimator() {
        super();
        threshold = DEFAULT_THRESHOLD;
    }

    /**
     * Constructor.
     *
     * @param listener listener to be notified of events such as when
     *                 estimation starts, ends or its progress significantly changes.
     */
    public PROSACRadialDistortionRobustEstimator(final RadialDistortionRobustEstimatorListener listener) {
        super(listener);
        threshold = DEFAULT_THRESHOLD;
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @throws IllegalArgumentException if provided lists of points don't have
     *                                  the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
     */
    public PROSACRadialDistortionRobustEstimator(
            final List<Point2D> distortedPoints, final List<Point2D> undistortedPoints) {
        super(distortedPoints, undistortedPoints);
        threshold = DEFAULT_THRESHOLD;
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param listener          listener to be notified of events such as when
     *                          estimation starts, ends or its progress significantly changes.
     * @throws IllegalArgumentException if provided lists of points don't have
     *                                  the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final RadialDistortionRobustEstimatorListener listener) {
        super(distortedPoints, undistortedPoints, listener);
        threshold = DEFAULT_THRESHOLD;
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param distortionCenter  radial distortion center. If null it is assumed
     *                          to be the origin of coordinates, otherwise this is typically equal to
     *                          the camera principal point.
     * @throws IllegalArgumentException if provided lists of points don't have
     *                                  the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final Point2D distortionCenter) {
        super(distortedPoints, undistortedPoints, distortionCenter);
        threshold = DEFAULT_THRESHOLD;
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param distortionCenter  radial distortion center. If null it is assumed
     *                          to be the origin of coordinates, otherwise this is typically equal to
     *                          the camera principal point.
     * @param listener          listener to be notified of events such as when
     *                          estimation starts, ends or its progress significantly changes.
     * @throws IllegalArgumentException if provided lists of points don't have
     *                                  the same size or their size is smaller than MIN_NUMBER_OF_POINTS.
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final Point2D distortionCenter,
                                                 final RadialDistortionRobustEstimatorListener listener) {
        super(distortedPoints, undistortedPoints, distortionCenter, listener);
        threshold = DEFAULT_THRESHOLD;
    }

    /**
     * Constructor.
     *
     * @param qualityScores quality scores corresponding to each provided point.
     * @throws IllegalArgumentException if provided quality scores length is
     *                                  smaller than required size (i.e. 2 points).
     */
    public PROSACRadialDistortionRobustEstimator(final double[] qualityScores) {
        this();
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor.
     *
     * @param qualityScores quality scores corresponding to each provided point.
     * @param listener      listener to be notified of events such as when
     *                      estimation starts, ends or its progress significantly changes.
     * @throws IllegalArgumentException if provided quality scores length is
     *                                  smaller than required size (i.e. 2 points).
     */
    public PROSACRadialDistortionRobustEstimator(
            final double[] qualityScores, final RadialDistortionRobustEstimatorListener listener) {
        this(listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param qualityScores     quality scores corresponding to each provided point.
     * @throws IllegalArgumentException if provided lists of points and quality
     *                                  scores don't have the same size or their size is smaller than
     *                                  MIN_NUMBER_OF_POINTS (i.e. 2 points).
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final double[] qualityScores) {
        this(distortedPoints, undistortedPoints);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param qualityScores     quality scores corresponding to each provided point.
     * @param listener          listener to be notified of events such as when
     *                          estimation starts, ends or its progress significantly changes.
     * @throws IllegalArgumentException if provided lists of points or quality
     *                                  scores don't have the same size or their size is smaller than
     *                                  MIN_NUMBER_OF_POINTS (i.e. 2 points).
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final double[] qualityScores,
                                                 final RadialDistortionRobustEstimatorListener listener) {
        this(distortedPoints, undistortedPoints, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param qualityScores     quality scores corresponding to each provided point.
     * @param distortionCenter  radial distortion center. If null it is assumed
     *                          to be the origin of coordinates, otherwise this is typically equal to
     *                          the camera principal point.
     * @throws IllegalArgumentException if provided lists of points or quality
     *                                  scores don't have the same size or their size is smaller than
     *                                  MIN_NUMBER_OF_POINTS (i.e. 2 points).
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final double[] qualityScores,
                                                 final Point2D distortionCenter) {
        this(distortedPoints, undistortedPoints, distortionCenter);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Constructor.
     *
     * @param distortedPoints   list of distorted points. Distorted points are
     *                          obtained after radial distortion is applied to an undistorted point.
     * @param undistortedPoints list of undistorted points.
     * @param qualityScores     quality scores corresponding to each provided point.
     * @param distortionCenter  radial distortion center. If null it is assumed
     *                          to be the origin of coordinates, otherwise this is typically equal to
     *                          the camera principal point.
     * @param listener          listener to be notified of events such as when
     *                          estimation starts, ends or its progress significantly changes.
     * @throws IllegalArgumentException if provided lists of points or quality
     *                                  scores don't have the same size or their size is smaller than
     *                                  MIN_NUMBER_OF_POINTS (i.e. 2 points).
     */
    public PROSACRadialDistortionRobustEstimator(final List<Point2D> distortedPoints,
                                                 final List<Point2D> undistortedPoints,
                                                 final double[] qualityScores,
                                                 final Point2D distortionCenter,
                                                 final RadialDistortionRobustEstimatorListener listener) {
        this(distortedPoints, undistortedPoints, distortionCenter, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to determine whether points are inliers or not when
     * testing possible estimation solutions.
     * The threshold refers to the amount of error (i.e. Euclidean distance) a
     * possible solution has on projected 2D points.
     *
     * @return threshold to determine whether points are inliers or not when
     * testing possible estimation solutions.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether points are inliers or not when
     * testing possible estimation solutions.
     * The threshold refers to the amount of error (i.e. Euclidean distance) a
     * possible solution has on projected 2D points.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if robust estimator is locked because an
     *                                  estimation is already in progress.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (isLocked()) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided point.
     * The larger the score value the better the quality of the sampled point.
     *
     * @return quality scores corresponding to each point.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided point.
     * The larger the score value the better the quality of the sampled point.
     *
     * @param qualityScores quality scores corresponding to each point.
     * @throws LockedException          if robust estimator is locked because an
     *                                  estimation is already in progress.
     * @throws IllegalArgumentException if provided quality scores length is
     *                                  smaller than MINIMUM_SIZE (i.e. 2 samples).
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (isLocked()) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates if estimator is ready to start the radial distortion
     * estimation.
     * This is true when input data (i.e. 2D points and quality scores) are
     * provided and a minimum of 2 points are available.
     *
     * @return true if estimator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == distortedPoints.size();
    }

    /**
     * Estimates a radial distortion using a robust estimator and
     * the best set of matched 2D points found using the robust estimator.
     *
     * @return a radial distortion.
     * @throws LockedException          if robust estimator is locked because an
     *                                  estimation is already in progress.
     * @throws NotReadyException        if provided input data is not enough to start
     *                                  the estimation.
     * @throws RobustEstimatorException if estimation fails for any reason
     *                                  (i.e. numerical instability, no solution available, etc).
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public RadialDistortion estimate() throws LockedException, NotReadyException, RobustEstimatorException {
        if (isLocked()) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<RadialDistortion>(new PROSACRobustEstimatorListener<>() {

            // point to be reused when computing residuals
            private final Point2D testPoint = Point2D.create(CoordinatesType.INHOMOGENEOUS_COORDINATES);

            // non-robust radial distortion estimator
            private final LMSERadialDistortionEstimator radialDistortionEstimator = new LMSERadialDistortionEstimator();

            // subset of distorted (i.e. measured) points
            private final List<Point2D> subsetDistorted = new ArrayList<>();

            // subset of undistorted (i.e. ideal) points
            private final List<Point2D> subsetUndistorted = new ArrayList<>();

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return distortedPoints.size();
            }

            @Override
            public int getSubsetSize() {
                return RadialDistortionRobustEstimator.MIN_NUMBER_OF_POINTS;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<RadialDistortion> solutions) {
                subsetDistorted.clear();
                subsetDistorted.add(distortedPoints.get(samplesIndices[0]));
                subsetDistorted.add(distortedPoints.get(samplesIndices[1]));

                subsetUndistorted.clear();
                subsetUndistorted.add(undistortedPoints.get(samplesIndices[0]));
                subsetUndistorted.add(undistortedPoints.get(samplesIndices[1]));

                try {
                    radialDistortionEstimator.setPoints(distortedPoints, undistortedPoints);
                    radialDistortionEstimator.setPoints(subsetDistorted, subsetUndistorted);

                    final var distortion = radialDistortionEstimator.estimate();
                    solutions.add(distortion);
                } catch (final Exception e) {
                    // if anything fails, no solution is added
                }
            }

            @Override
            public double computeResidual(final RadialDistortion currentEstimation, final int i) {
                final var distortedPoint = distortedPoints.get(i);
                final var undistortedPoint = undistortedPoints.get(i);

                currentEstimation.distort(undistortedPoint, testPoint);

                return testPoint.distanceTo(distortedPoint);
            }

            @Override
            public boolean isReady() {
                return PROSACRadialDistortionRobustEstimator.this.isReady();
            }

            @Override
            public void onEstimateStart(final RobustEstimator<RadialDistortion> estimator) {
                try {
                    radialDistortionEstimator.setLMSESolutionAllowed(false);
                    radialDistortionEstimator.setIntrinsic(getIntrinsic());
                } catch (final Exception e) {
                    Logger.getLogger(PROSACRadialDistortionRobustEstimator.class.getName()).log(Level.WARNING,
                            "Could not set intrinsic parameters on radial distortion estimator", e);
                }

                if (listener != null) {
                    listener.onEstimateStart(PROSACRadialDistortionRobustEstimator.this);
                }
            }

            @Override
            public void onEstimateEnd(final RobustEstimator<RadialDistortion> estimator) {
                if (listener != null) {
                    listener.onEstimateEnd(PROSACRadialDistortionRobustEstimator.this);
                }
            }

            @Override
            public void onEstimateNextIteration(
                    final RobustEstimator<RadialDistortion> estimator, final int iteration) {
                if (listener != null) {
                    listener.onEstimateNextIteration(PROSACRadialDistortionRobustEstimator.this, iteration);
                }
            }

            @Override
            public void onEstimateProgressChange(
                    final RobustEstimator<RadialDistortion> estimator, final float progress) {
                if (listener != null) {
                    listener.onEstimateProgressChange(PROSACRadialDistortionRobustEstimator.this, progress);
                }
            }

            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }
        });

        try {
            locked = true;
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            return innerEstimator.estimate();
        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } finally {
            locked = false;
        }
    }

    /**
     * Returns method being used for robust estimation
     *
     * @return method being used for robust estimation
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Sets quality scores corresponding to each provided point.
     * This method is used internally and does not check whether instance is
     * locked or not
     *
     * @param qualityScores quality scores to be set
     * @throws IllegalArgumentException if provided quality scores length is
     *                                  smaller than MINIMUM_SIZE
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores.length < MIN_NUMBER_OF_POINTS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}